One-pot synthesis of highly emissive dipyridinium dihydrohelicenes

Amedeo Santoro, Rianne M. Lord, Jonathan J. Loughrey, Patrick C. McGowan, Malcolm A. Halcrow, Adam F. Henwood, Connor Thomson, Eli Zysman-Colman

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9 Citations (Scopus)


Condensation of a pyridyl‐2‐carbaldehyde derivative with 2‐(bromoethyl)amine hydrobromide gave tetracyclic pyrido[1,2‐a]pyrido[1′,2′:3,4]imidazo‐[2,1‐c]‐6,7‐dihydropyrazinium dications in excellent yields. Crystal structures and NOE data demonstrated the helical character of the dications, the dihedral angles between the two pyrido groups ranging from 28–45°. An intermediate in the synthesis was also characterized. A much brighter emission compared to literature helicenes has been found, with quantum yields as high as 60 % in the range of λ=460–600 nm. Preliminary cytotoxicity studies against HT‐29 cancer cells demonstrated moderate‐to‐good activity, with IC50 values 12–30× that of cisplatin.
Original languageEnglish
Pages (from-to)7035-7038
Number of pages4
JournalChemistry - A European Journal
Issue number19
Early online date24 Mar 2015
Publication statusPublished - 4 May 2015

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